Split-Trunk Trees Are Shot

Don’t bother trying to put them back together

By Dr. Francis Gouin

Irene left us many trees with split trunks. Splitting occurs mostly on shade trees with narrow crotches. Narrow crotches are weak and break easily when strong winds whip the branches back and forth.
I have seen many people, including arborists, bolt these trees back together. It may seem that the operation was a success. But within eight to 10 years, the patient will have developed a good case of heart rot, and the tree will become a hazard.

Fertilize Hollies in the Fall

Q I enjoy reading your articles in Bay Weekly. I took your advice on hollies (March 23) and gave several a really severe pruning. These include three China Girls and a Nellie Stevens. I typically use Holly-tone on all of my hollies, magnolias and azaleas, with both spring and fall applications.
Am I understanding your article correctly — that I should not immediately fertilize hollies that received significant pruning? If so, when should I resume the fertilizing? Also, I have four large Nellie Stevens that I did not prune at all this spring. Should I go ahead and fertilize them?

–Tim O’Hara, Gambrills

A Do not fertilize hollies that have been pruned severely. Resume fertilizing this October.
If you fertilize fruiting hollies in the fall, you maintain better foliage color, especially if there is a heavy fruit set. Producing red berries on hollies requires lots of nitrogen, which is translocated from the foliage, making the foliage pale green.

As soon as a tree’s sapwood is exposed to air, as when a tree trunk splits, it becomes contaminated with microorganisms. Even if you were to try and sterilize the splintered surface before bolting it back together, total sterilization is impossible. By bolting the trunk back together, you create a perfect incubation chamber for wood-decaying microorganisms to grow and propagate.
In the first year following the operation, the tree may appear healthy and may be forming callus tissues along the damaged area. However, internally the microorganisms are slowly and methodically digesting the wood fibers, causing the wood to decay and rot.
Internal decay in trees, known as heart rot, is not noticeable unless you are looking for it. Carpenter ants entering the tree are a sure sign, as are mushrooms growing on the trunk. Branch dieback can sometimes be seen, mostly from the splintered branch. Premature fall color is another symptom to look for on the affected branch.
If the affected tree is large and the split is a single branch that can be spared without seriously affecting its appearance, you can often save the tree by sacrificing the limb. Smooth the edges of the bark along the cuts with a draw-blade or carpenter’s chisel. Remove splinters inside the wound and make the wood smooth. Never paint or apply tree wound dressing to such wounds, and never fill them with cement or wood filler. If the bottom of the wound is square and can collect water, cut a small V for the water to drain.